TVS tube selection calculation, the dissipated power of the TVS component is greater than the waveform power according to this standard? Here is the test waveform...

QWE4562009

TVS tube selection calculation, the dissipated power of the TVS component is greater than the waveform power according to this standard? Here is the test waveform... [Copy link]

 

TVS tube selection calculation, the dissipated power of the TVS component is greater than the waveform power according to this standard? I don't understand the power calculation of the test waveform here.

langtuodianzi

The peak pulse power rating of a TVS diode is defined as the instantaneous power dissipated by the device under given pulse conditions and is a measure of the power dissipated in the TVS tube during a given transient event. It is calculated by the following relationship: P PP = VC x I PP, where P PP = peak pulse power (W), VC = clamping voltage (V), and I PP = peak pulse current (A).

Pp = Vc X lpp

Many low power TVS diodes used for electrostatic discharge (ESD) protection use an 8/20s pulse as a reference.

When considering the parameters of the rated pulse power of the TVS tube, the actual transient pulse waveform must be taken into account. If the actual pulse duration is shorter than 10/1000us, the TVS tube can absorb a transient power greater than the rated pulse power value, and the tube itself will not be damaged.

In practical applications, the maximum power that the TVS tube may absorb during a lightning surge overvoltage should be estimated, and the pulse power value of the TVS tube should be selected according to the actual duration of the transient current waveform. If it needs to be used in a harsh environment, an enhanced protection design (graded protection) can be used. As shown in the following figure:

QWE4562009

langtuodianzi posted on 2021-9-15 16:10 The peak pulse power rating of a TVS diode is defined as the instantaneous power dissipated by the device under given pulse conditions and is the peak power dissipated by the TVS diode during a given transient event.

You seem to be a professional

1.What does 10/1000us mean?

2. What are the differences between bidirectional TVS and unidirectional TVS? When are they used?

3. The above calculations are not for my graph

langtuodianzi

1 ) 10/1000 μs waveform, simply means: the rising edge is 10us, the half-peak value is 1000us, and the standard IEC61000-4-5 has a detailed definition.

2 ) Bidirectional TVS is often used in situations where there is alternating current or positive and negative bidirectional pulses. If the circuit only has positive level signals, a unidirectional TVS will suffice.

qwqwqw2088

qwqwqw2088

QWE4562009

qwqwqw2088 posted on 2021-9-15 19:12

The resistance here is 2R.

QWE4562009

qwqwqw2088 posted on 2021-9-15 19:18

What curve is this?

qwqwqw2088

QWE4562009 posted on 2021-9-16 16:53 What kind of curve is this

10/1000μs test waveform

QWE4562009

qwqwqw2088 posted on 2021-9-16 17:38 10/1000μs test waveform

What does this mean? 1000us accounts for 10us?

qwqwqw2088

QWE4562009 posted on 2021-9-16 18:34 What does this mean? 1000us accounts for 10us?

Is it not clear what the netizen of Langtuo Electronics introduced on the 4th floor?

I suggest you read the reply carefully, it is a very professional explanation.

qwqwqw2088

The 4th floor has explained it very clearly.

qwqwqw2088

QWE4562009

langtuodianzi published on 2021-9-15 17:51 1) 10/1000 μs waveform, simply means: the rising edge is 10us, the half peak value is 1000us, the standard IEC61000-4-5 has a detailed definition. 2) Double...

Why not full peak?

QWE4562009

qwqwqw2088 posted on 2021-9-16 19:48 Is the introduction of the netizen of Langtuo Electronics on the 4th floor still unclear? I suggest you take a closer look at the reply from the person who replied. It is a very professional explanation...

When I replied, he hadn't sent it out yet...